Airports, aerodromes, and airfields today can be very congested spaces and must often support ground operations of a larger number of aircraft than the facility was originally designed to handle. Directing all of this ground traffic efficiently and safely requires effective communication between an aircraft's cockpit crew, ground control, and ground operations personnel. In most airports, multiple landing aircraft must be safely directed from touch down locations along and across runways and taxiways to a gate or other parking location while multiple departing aircraft are simultaneously pushed back and directed to takeoff locations, often along and across the same runways. The operation of airlines and airports today focuses on achieving maximum efficiency to keep operating costs as low as possible while continuing to provide travelers with a safe and economical mode of travel. It is desired to keep the time an aircraft spends on the ground at an airport between arrival at and departure from the gate to the minimum required to unload arriving passengers and cargo, service the aircraft, and load departing passengers and cargo. Minimizing this turnaround time not only reduces delays in airline flight schedules, but also increases the possibility that an airline can schedule additional flights, providing travelers with more options and improving airline profits. Increased aircraft ground traffic, however, may be accompanied by an increased risk of ground incidents involving aircraft, ground vehicles, and even passengers and ground personnel. Consequently, reducing aircraft turnaround time should not be at the expense of increased ground safety risks.
Establishing and maintaining communications between an aircraft flight crew and ground operations personnel is particularly important in an airport ramp area. The ramp entry or exit area, which is the area adjacent to a taxiway and leading to or from an airport's gates or terminal is, according to some studies, the location of most ground incidents. At this location, taxi lines leading into and out of the gate area converge, and an aircraft is less likely to be in communication with air traffic or other controllers. Flight crew are more likely at this point to be relying on an airline's ramp control procedure or ground personnel input for guidance. The largest percentage of incidents in one study occurred within 20 feet of the nose wheel parking line, within the gate stop area, when the flight crew is typically relying entirely on ground personnel guidance and signals for clearance from obstacles and for final taxi instructions. Ramp congestion caused by increasing numbers of flights, stringent aircraft scheduling requirements, and efforts to squeeze large jets into gates originally designed for much smaller aircraft contributes to traffic jams and reduced maneuvering space in the ramp area. Current requirements for the pushback tugs and tow vehicles needed to move departing aircraft away from gates, as well as requirements for other ground vehicles, add to ramp congestion. Increased ramp congestion may be exacerbated by poor communication and inadequate numbers of ground personnel, leading to the likelihood of increased ramp incidents. Establishing and maintaining effective communication between an aircraft's cockpit crew and ground personnel operating tugs and ground service vehicles is essential if airport ground operations are to be conducted efficiently and safely.
One study found that more incidents occur during aircraft arrival than during departure. One possible explanation for this is that there may be more obstacles for an aircraft to encounter when entering the congested area next to gates and terminal buildings. Another reason may be related to the large number of pushback, power-out, and power-turn procedures that are currently conducted during departure operations while arriving aircraft are entering the ramp area. Communication between an aircraft's flight crew and ground personnel may not have been as clearly established as it should have been. It has been estimated that ramp incidents and injuries cost airlines about US$10 billion each year.
Ramp safety, and airport ground safety generally, can be significantly compromised by the potential hazards associated with the operation of an aircraft's engines to move an aircraft on the ground, especially from jet blast and engine ingestion when aircraft engines are kept in operation, even at idle speeds. The attachment and subsequent detachment of pushback tugs or tow vehicles from departing aircraft can also impact ground safety. Incidents resulting from these potential hazards can be completely avoided, and communication between an aircraft's flight crew and ground operations personnel can be clearest and most effective, only when the aircraft engines are shut down and remain off. Maintaining effective communications between an aircraft's flight crew and ground personnel in a ramp area is critical for safe aircraft ramp operations.
The use of a drive means, such as a motor structure, mounted with a wheel to rotate the wheel an aircraft and move the aircraft on the ground without operation of the aircraft's main engines has been proposed. U.S. Pat. No. 7,445,178 to McCoskey et al, for example, describes electric nose wheel drive motors intended to drive aircraft during taxi. U.S. Pat. No. 7,469,858 to Edelson; U.S. Pat. No. 7,891,609 to Cox; U.S. Pat. No. 7,975,960 to Cox; U.S. Pat. No. 8,109,463 to Cox et al; and British Patent No. 2457144, owned in common with the present invention, describe aircraft drive systems that use electric drive motors to power aircraft wheels and move an aircraft on the ground without reliance on aircraft main engines or external tow vehicles. While eliminating the use of an aircraft's engines to move an aircraft into and out of a ramp area should avoid the aforementioned hazards and improve the safety of ramp operations, the foregoing art does not suggest the additional improvements in safety and efficiency of ground operations that can be achieved by equipping an aircraft with a drive wheel drive system for autonomous ground movement and an effective wireless onboard to ground communication system useful to assist in guiding the aircraft as it moves without engines or tow vehicles.
Communications systems to enable ground personnel to direct the travel of incoming and outgoing aircraft in the ramp area are available. Such systems range from hand signals used by ground personnel, including wing walkers and others, to voice communications transmitted between ground personnel and an aircraft's flight crew. An airport ramp where aircraft use their engines to power movement into and out of the ramp area can be a very noisy environment, and voice communications transmissions can be difficult to hear, even with headphones and other equipment intended to block out background noise. The potential for miscommunication of important information can be significant. While advances in communication technology have produced some improvements, as long as aircraft engines are operating, there will be a high level of noise in the ramp area.
One currently available communication system, supplied by Flightcom Corp. of Portland, Oreg., is a wireless pushback communication system that includes the aircraft's Interphone and is designed to enable and control communication among ground personnel, an aircraft's flight crew, and a pushback tug or tractor operator during the pushback process. A portable communications module is provided for use in the aircraft cockpit to connect wireless, Interphone, and a pushback tug or tractor operator during the pushback process. When the pushback process has been completed, the module is removed from the aircraft. The communication module is not intended to remain on the aircraft and specifically includes alerts that communicate to an aircraft flight crew that the module has been left onboard and should be removed. There is no suggestion, moreover, that this communication system could be part of a substantially permanent onboard to ground operations wireless communication system installed in an aircraft and designed to interface universally with ground communications systems to increase ground travel efficiency in aircraft equipped with drive wheel drive systems for autonomous ground operations, including taxi and pushback.
A need exists for a permanent onboard to ground operations wireless communications system installed in an aircraft that is designed to interface universally with virtually all airport, aerodrome, and airfield ground operations communications systems to establish and maintain effective communication between an aircraft's pilot or flight crew and ground personnel during ground operations. Such a communications system is needed to improve efficiency of taxi, parking near a terminal, and pushback in any airport, aerodrome, or airfield where an aircraft equipped with both an onboard to ground wireless communications system and a pilot-controlled drive wheel drive system for autonomous ground movement lands.